Hoppers and tank trailers have been commonly used to transport bulk commodities such as granular product or dry bulk material, including industrial products and food products. The hoppers may include multiple sections or compartments for receiving and holding the commodities, with each section or compartment having a generally conical or tapered bottom portion terminating at a discharge outlet. A discharge valve, such as a butterfly valve, is typically provided at the discharge outlet and when opened will allow the commodities to flow out of the tank trailer.
When the hopper or the tank trailer reaches its destination, the bulk commodity will be unloaded by use of a pressurized air system. Typically, this is accomplished by connecting tee assemblies for unloading and then initiating the pneumatic unloading of the bulk commodity from the hopper into a clean and sanitary pipe line. In this manner, the tee assemblies are connected at opposite ends thereof to generally horizontal pipes or hoses that are connected, in turn, to the hopper tees of other sections or compartments. These connections establish a generally horizontal path through the hopper tees and connected pipes or hoses for the flow of the materials discharged from the hopper sections or compartments.
Actual transfer of the bulk commodity that has been transported in the hopper is then accomplished by opening the discharge or dump valve, typically a butterfly valve, associated with the discharge outlet at the bottom of the hopper. Once the valve is opened, the bulk commodity material is moved out of the hopper by gravity flow or by air pressure vibration into and through the vertical section of the hopper tee. As the bulk commodity material drains through the vertical section of the hopper tee into the horizontal portion of the hopper tee, the material is directionally directed by air conveyance through the horizontal portion by a pressure differential in the pipe to cause the material to be directed to and discharged to a desired receptacle or area.
The butterfly valve is generally configured to be manually operated by a rotatable valve stem that projects generally outwardly and generally horizontally near the top of the vertical section of the hopper tee. The valve stem may be engaged by a valve handle so as to be rotated by the operation of the valve handle to open and close the valve. Typically, the projecting portion of the valve stem has been formed or machined at its outer end to have a non-circular cross-section so as to be easily engaged by a similarly configured socket portion associated with the valve handle.
Because the discharge valve for the hopper is positioned at the bottom of the hopper, access to the valve for purposes of opening and closing the valve is often inconvenient. Due to the limited ground clearance height of the valve and the valve being generally centered below the hopper, the valve is difficult to easily reach. Further, a valve handle device must frequently be employed by an operator to assist in actuating the discharge valve. Use of the valve handle device puts the operator in awkward or less than desirable position. Consequently, over the years, it has become desirable, if not customary, for valve handle devices to be constructed from aluminum or other lighter weight materials so as to lessen the strain on the operator as the operator attempts to handle and utilize the valve handle device in awkward positions.
The butterfly valve is used at the base of tank trailers, or even railroad cars, as a means to prevent the untimely discharge of the conveying cargo, whether it is grains, polymer beads, or other flowable materials. The butterfly valve may be manipulated into an open position to provide for the prompt discharge of material from the tank trailer or hopper. Usually, in order to gain access to the butterfly valve to operate the valve, the operator of the vehicle was required to climb under the tank trailer and in the early days, apply a wrench to the butterfly valve shaft, and forcefully turn it at least a quarter turn, in order to provide for opening or closing of the valve, during its manipulation and operation. The problem with such structure was its accessibility, because the operator was required to crawl deeply under the vehicle, to obtain access to the shaft, and to attain its manipulation, during usage. During inclement weather, obviously, this is a dirty task, but, regardless of the weather, it was still predominantly a difficult task. Also, the butterfly valve is in close proximity to hot air supply lines that can reach temperatures of 350° F. If caution is not exercised, it is possible that the operator may be burned by coming into contact with the hot air supply lines.
Consequently, there has existed a need for an improved butterfly valve extension assembly that can be more easily operated by a user without encountering undue interference with other equipment or piping at the bottom on the hopper. It would also be desirable to avoid any potentially hazardous conditions such as coming into contact with hot air lines or being near a tremendous amount of material being discharged. It would also be advantageous to provide a multi-angle butterfly valve extension assembly that is designed to enhance the safety and convenience of the vehicle operator, and to facilitate easy manipulation of a butterfly valve when unloading of a tank trailer.